"Though the military response to Boko Haram has become more cogent, the Lake Chad states should not too quickly proclaim 'mission accomplished'," the International Crisis Group said.
"Even if they are made to abandon all territorial pretensions in Nigeria's northeast and the Lake Chad area, or are forced to abandon their guerrilla war, some Boko Haram militants at least are likely to seek to continue their insurgency in some form, probably through terror attacks," the security analysts added.
The ICG said the meeting -- two years after the first in Paris -- was "an opportunity to consolidate regional and wider international cooperation" as well as review current policies.
Closer ties beyond military support were vital to address key drivers of the conflict, as well as its effects, to prevent sustained support for the Islamists and similar, future threats.
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These include addressing the humanitarian situation for the more than 2.8 million people made homeless by the violence since 2009, and re-establishing the rule of law and governance in the region.
"How governments treat and distinguish Boko Haram ideologues from those who joined from other motives will be vital," the report said.
"Dealing appropriately with ex-members is the first step to lessen recruitment."
Nigeria's military on Tuesday said dozens of Boko Haram fighters were now at a rehabilitation camp in an undisclosed location and undergoing a "deradicalisation" programme.
President Muhammadu Buhari, who has made defeating Boko Haram a priority since taking power last year, in December declared that the Islamic State group affiliate was "technically" defeated.
But the rebels have still been able to deploy suicide bombers in northeast Nigeria, and particularly northern Cameroon, even if attacks have decreased in Chad and Niger.
The ICG recommended winding down the use of civilian militia forces who have helped the military maintain security but also been accused of abuses against civilians.